Barnes, Grace, author
D. C. Health , 1946
Buku Teks
Columbia : Columbia University Press and American Dialect Society
Majalah, Jurnal, Buletin
Levy, Leonard W., author
Harper, 1963
Buku Teks
Buckley, Lillian A., author
Citation Press, 1975
Buku Teks
Seoul Selection, 2011
Buku Teks